1246610 玖、發明說明： 【發明所屬之技術領域】 本發明係一種面狀光源裝置及採用該面狀光源裝置之影 像讀取裝置，其使導光體背面側具備光散射功能，使得光 以均勻地射出。 【先前技術】 先前技術的面狀光源裝置中，例如揭示於日本專利特開 2 0 0 1 - 3 4 2 1 0號公報者已為周知。該公報所示的面狀光源裝 置示於圖1。圖1所示之面狀光源裝置，具備由透明丙烯 酸樹脂所成的平面導光體1 2，該平面導光體1 2中相對短 邊側的側面中央處，分別具有L E D光源1 4 a、1 4 b。此外， 在平面導光體12的整個背面13上形成有光散射體。平面 導光體1 2的底面被白色底板1 6覆蓋，而四周側面則被白 色框架18包圍。在平面導光體12的頂面（發光面）裝有擴 散片20。 該面狀光源裝置，採用使來自點光源的光射入於透明材 的平面導光體内，並使光得以均勻地從二維面狀部分發光 之裝置，以使來自作為點光源之LED光源的光，轉換成來 自於面狀光源的發光分布。 此外，每一點光源配置於平面導光體的相對兩面側上之 架構中，一方光源的光量所帶來的面内輝度分布及另一方 光源的光量所帶來的面内輝度分布相補，且透過雙方總和 的面内輝度分布，以獲得最後的均勻輝度分布。 然而，上述面狀光源裝置中，若欲增加LED光源而實現 5 312/發明說明書(補件)/92-08/92113847 1246610 多色化及光量增大，即會產生下述問題： 若欲將來自於點光源的光轉換成來自面狀光源之光的發 光分布而使光以均勻地從二維面狀部分處發光，就必須在 平面導光體背面上形成精密度調整極佳的光學散射體。但 是，形成於平面導光體背面上的光學散射體，通常僅能對 於來自單一 L E D模組的發光（來自略單一點的發光）以均勻 地散射而調整者。調整成對應來自單一點的發光（點光 源），在相鄰處配設新的點光源時，對於新的點光源會產生 光量調整上的偏差，結果，導致在面狀光源上輝度分布不 均勻，因此難以間隔裝設複數個L E D模組。 從而，因受到如上述限制而難免裝設於平面導光體上的 L E D模組限為單一個。通常，單一個L E D模組（例如，日商 曰亞化學工業（股）製的NSCM315C型）上，分別裝載有 R (紅）、G (綠）、B (藍）各1總計共3個晶片。若裝載更多之 晶片，則會因發熱元件封裝於面積有限的基板上，無法進 行冷卻作用而造成整片基板昇溫，導致LED的光學性能下 降。於是，例如裝載有R、G、B的三種L E D的L E D模組上， 通常無法同時裝載除此之外的元件，故使其成為限定元件 (數量或顏色）之面狀光源。換言之，其難以多色化或光量 增大。 另外，光源裝設於平面導光體的相對兩面側處時，必須 採用同一種光源，否則無法實現整體均勻的輝度分布。僅 在將同一種光源呈對置配置時，透過光量累積才能獲得均 勻的面狀發光，而在將不同種點光源呈對置配置時，則無 6 312/發明說明書(補件)/92-08/92113 847 1246610 法累積光量，故呈現異常面内光量分布之情形。 更且，採用LED光源時，雖然是同一種也會有光量偏差。 LED光源，通常在同一產品中也有很大的光量偏差，且在 規格上，光輸出能力的最大/最小比率為3至4倍，若不同 光輸出能力者使其等配合時就在加乘上產生不均衡，無法 獲得均勻的輝度分布。 本發明係為了解決先前技術的問題者，其目的在於提供 一種面狀光源裝置及利用該面狀光源裝置之影像讀取裝 置，該面狀光源裝置，係將複數個L E D光源配置於導光體 的端面部處，以能實現多種類（多顏色）或同色複數（光量增 大）的L E D光源或其等結合。 【發明内容】 本發明的面狀光源裝置，其特徵為，具備：導光體，其 背面具有能散射光之光學散射體；以及，複數個光源，配 置於導光體端面部；該導光體，在導光體背面的光源近旁 處具有不存在光學散射體之區域，以使自光源射出之光導 入至導光體内部，並使光經過光學散射體予以散射後再從 導光體發光面射出。 另外，本發明的面狀光源裝置，其特徵為，具備：導光 體，其背面具有能散射光之光學散射體；以及，複數個光 源，配置於導光體端面部；該導光體，將來自於光源且朝 向在導光體背面具有光學散射體區域内每單位面積上光學 散射體佔有率較低的區域射出之光，導入至導光體内部， 並使光經過光學散射體予以散射後再從導光體發光面射 7 312/發明說明書(補件)/92-08/92113 847 1246610 出。 另外，本發明的面狀光源裝置，其特徵為，具 體，其背面具有能散射之光學散射體；以及，複參 配置於導光體端面部；該導光體，在導光體背面 旁處具有不存在光學散射體之區域，能使向在導 的具有光學散射體區域内每單位面積上光學散射 較低的區域射出之光，從光源導入至導光體内部 經過光學散射體予以散射後再從導光體發光面射 【實施方式】 其次，參照圖式針對本發明的第一實施形態加 圖2為顯示根據本發明的面狀光源裝置的第一 之分解立體圖。圖2所示的面狀光源裝置，係由 導光體21、用來覆蓋導光體21四周側面之框架 高反射率且配置於導光體2 1背面上的反射板2 4 反射板2 4背面上之底板2 5、配置於導光體2 1 了I 面）上的光擴散片2 6所構成者。 在導光體21上，裝設有第一 LED模組22a及； 模組2 2 b作為將光從端面處射入至導光體2 1之； 第一 L E D模組2 2 a，係裝設於導光體2 1的短邊 中央處，而第二L E D模組2 2 b，係裝設於導光體 側的側面中央處及側面端緣之間，並且第一 LED 及第二LED模組22b的光射出角度，均成為相同 模組2 2 a及第二L E D模組2 2 b，分別在其内部具 R (紅）、G (綠）、B (藍）的三個LED。 312/發明說明書(補件)/92-08/92113847 備：導光 l個光源， 的光源近 光體背面 體佔有率 ，並使光 出。 以說明。 實施形態 透明面狀 23、具有 、配置於 ί面（發光 第二 LED fe源。 側的側面 2 1的短邊 模組22a 。第一 LED 備相鄰的 8 1246610 導光體21，其尺寸為27x 50x 3. 5mm，並採用透明丙稀 酸樹脂。在導光體2 1背面上利用印刷技術形成有一種由圓 形白點所構成的散射體圖案。 在用來覆蓋導光體的框架23及底板25上採用白色聚碳 酸酯，而在光擴散片2 6上採用擴散膜片（木本公司製 100GM2) ° 反射板2 4，也可裝設於導光體21和底板2 5之間，採用 反射率較高的材料，例如採用鏡子或鋁薄膜等材料。反射 板2 4的反射率（反射光/入射光）較佳為高於9 0 %。 圖3為由背面（印刷面）方向視導光體2 1之立體圖。導 光體21的背面，如圖3所示，係由不存在光學散射體（或 幾乎不產生散射者）區域，亦即無效區2 7，以及印製有由 圓形白點所成之散射體圖案之印刷區2 8所構成。無效區 27,設置在第一 LED模組22a及第二LED模組22b近旁處， 而印刷區2 8，則離於第一 L E D模組2 2 a及第二L E D模組2 2 b 一定距離而設置。 圖4為顯示形成於印刷區上的散射體圖案之圖式。在導 光體21背面上，配置有無效區27且在離於LED模組一定 距離L的印刷區2 8上印製有如圖4所示的散射體圖案。在 此以黑色表示者，其為圓形白點2 9，此部分之反射率較 高。雖然在此以圓形點來形成散射體圖案，但是其不限於 圓形，也可正方形、菱形等多種變化。在圖4中，導光體 中，LED模組的光射出方向長度L0為50mm，而不存在散射 體的無效區27中，LED模組的光射出方向長度L為10mm。 9 312/發明說明書(補件)/92-08/92113847 1246610 圖5為顯示一種散射體圖案之圖式，該散射體圖案形成 於導光體背面整面上，以使得在導光體2 1的短邊側的側面 中央處僅具有第一 LED模組22a時，實現均勻的發光分布。 圖4所示的散射體圖案，係由圖5所示的散射體圖案中除 去在離於L E D模組側一定距離L處的圓形白點2 9後所剩餘 的圓形白點2 9等所構成之散射體圖案。 圖6至圖11，皆為在具有25x47mm尺寸的發光面之上 述架構的面狀光源裝置中，對LED模組施加電流而使面狀 光源裝置發光時的面内輝度分布測定結果。該等LED模 組，皆配置於導光體X軸值較大側上（圖中配置於4 7 m m 側）。至於輝度計，採用T0PC0N製BM7。針對在第一 LED 模組及第二L E D模組上採用R (紅）L E D的情形加以說明。在 圖6至圖11中，發光面以xy座標表示，發光面的一角作 為座標原點，測定間距為1 m m將X軸均分成4 6等分，Y軸 均分成2 3等分。縱轴作為測定輝度（單位為c d / m2)。 首先，針對設置在導光體短邊側的側面中央處和側面端 部之間的第二LED模組之光學特性加以說明。圖6、圖7、 圖8皆是顯示第二LED模組的光學特性之圖式。 圖6為顯示L = 0 m m時，亦即在導光體整面上形成散射體 圖案時的光學特性，並顯示採用圖5的散射體圖案的第二 LED模組時之光學特性。 圖7為顯示L = 6 m m時，亦即在L E D模組近旁6 m m處設置 有無效區時的光學特性，其在圖5的散射體圖案中，利用 除去從L E D模組側起6 m m範圍内圓形白點之後的散射體圖 10 312/發明說明書(補件)/92-08/92113847 1246610 案時的第二LED模組之光學特性。 圖8為顯示L二1 0 m m時，亦即在L E D模組近旁 置有無效區時的光學特性5其在圖5的散射體圖 用除去從L E D模組側起1 0 m m範圍内圓形白點之後 圖案時的第二LED模組之光學特性。 如圖7及圖8所示，在第二LED模組的光學特 過設置無效區（不存在散射體圖案之區域），以使 近旁處的巨大光量高峰得以減少，且若使無效區 1 0 m m時，就呈現光量高峰明顯降低。結果，除去 後方印刷區之光量平均值升高，可獲得有效區域 勻的面内輝度分布。換言之，透過圖5的散射體 光源近旁處散射之後從發光面射出的光，藉由設 就得以使光呈全反射且更有效地向後方傳導。 圖9、圖1 0、圖1 1，皆為顯示設置在導光體短 面中央處之第一 LED模組的光學特性。 圖9為顯示L = 0inm時，亦即在導光體整面上形 圖案時的光學特性，並顯示採用圖5的散射體圖 LED模組時之光學特性。 圖1 0為顯示L = 6 m m時，亦即在L E D模組近旁 置有無效區時的光學特性，其在圖5的散射體圖 除去從LED模組側起6mm範圍内圓形白點時的第 組之光學特性。 圖1 1為顯示L = 1 0 m m時，亦即在L E D模組近旁 設置有無效區時的光學特性，其在圖5的散射體 312/發明說明書(補件)/92-08/92113847 .0 m m處設 案中，利 的散射體 性中，透 LED模組 長度L為 無效區之 更亮且均 圖案且在 置無效區 邊側的側 成散射體 案的第一 5 m m處設 案中，當 一 LED 模 1 0 m m 處 圖案中， 11 1246610 當除去從L E D模組側起1 0 m m範圍内圓形白點時的第一 L E D 模組之光學特性。 如圖1 0及圖1 1所示，在第一 L E D模組的光學特性中， 透過設置無效區（不存在散射體圖案之區域），以使L E D模 組近旁處減少光量，並該降低光量的部分作為無效部分來 處理。有關該使用法而言，例如圖1 2所示，在發光面側設 置遮光板3 0用以覆蓋無效區，以覆蓋不均勻區域，得以不 均勻區域不再使用。此外，設置覆蓋無效區的遮光板3 0， 可防止從LED模組近旁處漏光。 如上述，第一實施形態，在發光的光射出角為相同的複 數個LED模組配置於導光體上的情形下，透過將不’存在散 射體之無效區設於LED模組近旁處，可解決在LED模組近 旁處所產生的輝度分布不均勻。其因為，將不存在光學散 射體的無效區設於LED模組近旁處，能使無效區以後所形 成的光學散射體，從較遠一點的距離處（遠超過無效區）觀 察距離幾mm左右的LED模組（點光源），故可使包含呈相鄰 的複數個LED模組之光源整體恰好視為點光源。此外，因 為可將複數個LED模組配置於導光體上，故可實現多種類 且增加光量的L E D面狀光源。 其次，參照圖式，針對本發明的第二實施形態加以說明。 圖1 3為顯示根據本發明的面狀光源裝置的第二實施形 態之分解立體圖。圖1 3所示的面狀光源裝置，係由具有去 角部39的透明面狀導光體31、用來覆蓋導光體31的五面 側面之框架3 3、具有高反射率且配置於導光體3 1背面上 12 312/發明說明書(補件)/92-08/92113 847 1246610 的反射板3 4、配置於反射板3 4背面上之底板3 5、配置於 導光體3 1頂面（發光面）上的光擴散片3 6所構成者。 在導光體31上，裝設有第一 LED模組32a及第二LED 模組3 2 b作為將光從端面處射入至導光體3 1之光源。 第一 L E D模組3 2 a，係裝設於導光體3 1的短邊側的側面 中央處，而第二LED模組32b，係裝設於導光體31的去角 部3 9處。第一 L E D模組3 2 a及第二L E D模組3 2 b，分別在 其内部具備相鄰的R (紅）、G (綠）、B (藍）的三個L E D。 導光體31，其尺寸為27x 58x 3.5mm。此外，導光體31， 係在配置有第一 L E D模組3 2 a之側上具有去角部3 9，該去 角部3 9係對於短邊方向以斜角0且朝向第一 L E D模組3 2 a 的光射出方向予以取角者。在導光體31上採用透明丙烯酸 樹脂。在導光體3 1背面上利用印刷技術來形成有一種由圓 形白點所構成的散射體圖案。 在用來覆蓋導光體的框架33及底板35上採用白色聚碳 酸酯，而在光擴散片3 6上採用擴散膜片（木本公司製 100GM2) ° 在反射板3 4上採用反射率較高的材料，例如採用鏡子 或鋁薄膜等材料。反射板3 4的反射率（反射光/入射光）較 佳為高於90%。 圖1 4為由背面（印刷面）方向視導光體3 1之俯視圖。導 光體3 1的背面，係由不存在光學散射體（或幾乎不產生散 射者）區域，亦即無效區3 7，以及印製有由圓形白點所成 之散射體圖案之印刷區3 8所構成，如圖1 3所示。導光體 13 312/發明說明書(補件)/92-08/92113847 1246610 3 1係在第一 LED模組32a的光射出方向長度為58mm。無效 區37，係朝向光射出方向延在10mm而設置在第一 LED模 組3 2 a近旁處，而印刷區3 8，係從1 0 m m處起朝向光射出 方向延在58mni處而設置在第一 LED模組32a上。 導光體3 1，係具有去角部3 9，該去角部3 9係對於短邊 方向以斜角0且朝向第一 LED模組32a的光射出方向予以 取角者。第一 L E D模組3 2 a，係裝設於導光體3 1的短邊側 的側面中央處，而第二L E D模組3 2 b，係裝設於導光體3 1 的去角部39處。 圖1 5為顯示形成於導光體背面的印刷區域上的散射體 圖案和L E D模組之間的相對位置之圖式。以黑色表示者， 其為圓形白點，具有較高的反射率。雖然在此以圓形點來 形成散射體圖案，但是其不限於圓形，也可正方形、菱形 等多種變化。 第一 L E D模組3 2 a，設置於導光體3 1的短邊側的側面中 央處，並將光朝向散射體圖案較稀疏的區域（每單位面積中 圓形白點佔有率不高的區域）射出。第二L E D模組3 2 b，係 設置成與第一 LED模組32a相鄰，且將光以第一 LED模組 32a之光射出方向斜呈角度0朝向散射體圖案較稀疏的區 域（每單位面積中圓形白點佔有率不高的區域）射出。 圖16至圖19，皆為在具有25x44mm尺寸的發光面之上 述架構的面狀光源裝置中，對於L E D模組施加電流而使面 狀光源裝置發光時的面内輝度分布測定結果。該等LED模 組，皆配置於導光體X軸值較大側上（圖中配置於4 4 m m 14 312/發明說明書(補件)/92-08/92113 847 1246610 側）。至於輝度計，採用Τ 0 P C 0 N製Β Μ 7。針對在第一 L E D 模組及第二L E D模組上採用R (紅）L E D的情形加以說明。在 圖16至圖19中，發光面以xy座標表示，發光面的一角作 為座標原點，測定間距為1 m m將X軸均分成4 3等分，Y軸 均分成2 3等分。縱軸作為測定輝度（單位為c d / m2 )。 圖1 6及圖1 7分別顯示在第二L E D模組設置面對於第一 L E D模組設置面傾斜呈1 5 °時之第一 L E D模組及第二L E D 模組的光學特性之圖式。如圖1 6所示，第一 LE D模組的面 内輝度分布，呈現較平坦的分布。此外，如圖1 7所示，第 二L E D模組的面内輝度分布，即使在L E D模組近旁處出現 光量高峰處，亦可獲得較均勻的分布。 相對於此，圖1 8及圖1 9分別顯示在第二L E D模組設置 面對於第一 LED模組設置面無傾斜時之第一 LED模組及第 二L E D模組的光學特性之圖式。如圖1 9所示，第二L E D 模組的面内輝度分布，在LED模組近旁處出現較大的光量 高峰處，其相較於圖1 7所示的第二LED模組的光學特性， 均勻性呈現明顯惡化。 由圖1 6至圖1 9所示的面内輝度分布之測定結果得知： 如圖16及圖18所示，在第一 LED模組，不論導光體是否 具備去角部，皆無發現光學特性上的差異。其因為，射入 至導光體（折射率約為1 . 5的媒介）内的光，幾乎保持定向 性而傳導、前進，也沒有能達到去角部的光，就呈現沒出 現去角部影響的輝度分布。 此外，圖1 7及圖1 9予以比較而得知：在圖1 7中，透 15 312/發明說明書(補件)/92-08/92113 847 1246610 過使第二L E D模組對於第一 L E D模組傾斜呈1 5 °，使得L E D 模組近旁處的光量高峰呈現大幅小於圖1 9的情況。其因 為，如圖1 5所示，將來自於第二L E D模組3 2 b的光朝向散 射體圖案較稀疏的區域射出之緣故。若第二L E D模組對於 第一 L E D模組傾斜呈1 5 °時，能使來自於在去角部所配置 的第二LED模組之大部分的光，避開造成較大光量高峰之 LED模組近旁處的印刷散射體，並朝向離較遠的散射體 處，使得在全面上均衡地產生光散射。 因而，本發明，係透過使第二LED模組對於第一 LED模 組呈傾斜，並將光朝向散射體圖案較稀疏的區域射出，可 實現多種且增加光量的LED面狀光源。 如圖1 7所示，關於第二L E D模組而言，就在L E D模組 近旁處產生光量高峰，因此也可裝設如圖12所示的遮光板 3 0 (用來覆蓋在LED模組側有產生光量高峰的區域），覆蓋 不均勻區域得以不均勻區域不再使用。 第二L E D模組的能採用斜角範圍小於1 °至4 5 ° ，較佳 在5 °至3 0 °内。本發明的特徵在於：具有複數個L E D模 組時，如圖1 5所示，於L E D模組設有傾斜角度，以能將光 朝向散射體較稀疏的區域射出。若該斜角較小，會使LED 模組和散射體圖案之間距離延長，且在這距離之間的發光 強度不強，故導致使不需要部分成為大面積的面狀光源， 這樣不理想。此外，若斜角大於4 5 ° ，以致光難以朝向長 邊方向傳導，也不理想。 另外，在第二實施形態中，如圖1 5所示採用一種能二 16 312/發明說明書(補件)/92-08/92113847 1246610 維變化的散射體圖案，以使LED模組的光朝向散射體圖案 較稀疏的區域射出。更佳為，在採用一種散射體圖案沒有 以二維變化，僅能朝向靠近LED模組側變疏而由此邊離越 遠變密的長邊方向以一維變化的散射體圖案時，也可使第 二LED模組對於第一 LED模組呈傾斜，以將光射出至導光 體中央處。 此外，在第二實施形態中，雖然於導光體上設置去角 部，並將第二LED模組配置於該去角部處，使得第二LED 模組對於第一 LED模組呈傾斜，但是並不一定要在導光體 上設置去角部，只要能使第二LED模組對於第一 LED模組 呈傾斜，且將光朝向散射體圖案較稀疏的區射出即可，第 二LED模組如何配置皆可。例如，亦可使第二LED模組呈 傾斜而配置於框架上。 此外，在第二實施形態中，雖然使第二LED模組32b的 光射出方向對於第一 L E D模組3 2 a的光射出方向呈傾斜而 配置於導光體31上，但如圖2 0所示，假如將第三L E D模 組3 2 c配置於導光體31上，可更提高光量均勻性。此時， 若中央處光量增大，也可排除第一 LED模組32a，且僅留 第二LED模組32b及第三LED模組32c。 更且，如圖2 1所示，圖2 0所示的面狀光源配置複數個， 也可提供大型的面狀光源裝置。亦即，配置η個光源，就 能製作成η倍大的光源。 另夕卜，在第一及第二實施形態中，雖然關於具有呈相鄰 配設R、G、Β的L E D之L E D模組中，僅針對採用R (紅）的 17 312/發明說明書(補件)/92-08/92113847 1246610 LED時的光學特性加以說明，但R、G、B的每一 LED呈相 鄰配設，因此在採用G (綠）及B (藍）的L E D時，也可得到同 樣結果。 此外，將紅外線L E D裝設於第一 L E D模組及第二L E D模 組上，再利用紅外線用輝度計進行測量，也可得到與本實 施形態相同結果。並且，將紫外線L E D裝設於第一 L E D模 組及第二LED模組上，再利用紫外線用輝度計進行測量， 也可得到與本實施形態相同結果。採用可見光LED而取代 紅外線或紫外線LED，因導光體的折射率也不依靠波長， 故出現與可見光的結条相同結果。 另外，使第一 LED模組具備R、G、B的LED，且使第二 LED模組具備R、G、B的LED，再使R、G、B同步而發光， 因為第一 LED模組及第二LED模組均為相同顏色，所以可 增高光量。至於LED模組的數量而言，其不限於2個，也 可裝設3個或更多。 此外，使第一 L E D模組具傷R、G、B的L E D，且使第二 L E D模組具備紅外線L E D，就可提供一種能發色R、G、B 及紅外光之面狀光源裝置。並且，使第二LED模組具備紫 外線L E D，就可提供一種能發色R、G、B及紫外光之面狀 光源裝置。 LED模組數量並不限於2個，也可裝設3個或更多，因 此第一 LED模組具備R、G、B的LED，且使第二LED模組 具備紅外線L E D，更作為第三L E D模組具備紫外線L E D，就 可提供一種能發色R、G、B和紅外線以及紫外光之面狀光 18 312/發明說明書(補件)/92-08/92113 847 1246610 源裝置。 再者，針對一種利用根據上述第一或第二實施形態所作 的面狀光源裝置之影像讀取裝置，加以說明。 圖2 2為顯示影像讀取裝置之剖視圖，該裝置採用根據 第一或第二實施形態所作的面狀光源裝置之一例。 圖2 2所示的影像讀取裝置，係接觸型影像感測器4 6裝 設於外殼4 3内，外殼頂面由平台玻璃4 5所構成。在平台 玻璃4 5上置放有薄膜原稿4 7，而在薄膜原稿4 7上方處設 置有根據上述實施形態所作的面狀光源裝置4 8。該面狀光 源裝置4 8，可内建於原稿蓋（未圖示），或者掃描薄模原稿 時與原稿蓋交換。 接觸型影像感測器4 6，其内部具有桿狀透鏡陣列4 9、 線形影像感測器4 2，且配置成靠近平台玻璃4 5。此外，該 接觸型影像感測器4 6，更内建有一種當讀取紙張原稿時所 需的線形照明裝置44，當讀取薄膜原稿時則滅燈。 接觸型影像感測器4 6，使其往一定方向往返移動，進行 讀取、掃描原稿。射出於面狀光源裝置48的光，射透薄膜 原稿4 7之後，經過桿狀透鏡陣列4 9再射入至線形影像感 測器42處。 如上述說明，本發明，係在發光的光射出角為相同的複 數個LED模組配置成間隔開之面狀光源裝置中，透過將不 存在光學散射體之無效區設於LED模組近旁處，可解決在 LED模組近旁處所產生的輝度分布不均勻，更且，可配置 複數個L E D模組，故可實現多種且增加光量的L E D面狀光 19 312/發明說明書(補件)/92-08/92113 847 1246610 源。 此外，本發明，透過將來自於LED模組的光朝向散射體 圖案較稀疏的區域射出，以可解決在LED模組近旁處所產 生的輝度分布不均勻，藉此可實現多種且增加光量的LED 面狀光源。 【圖式簡單說明】 圖1為顯示先前技術之面狀光源裝置之分解立體圖。 圖2為顯示根據本發明的面狀光源裝置的第一實施形態 之分解立體圖。 圖3為由背面（印刷面）方向視導光體之立體圖。 圖4為顯示形成於印刷區上的散射體圖案之圖式。 圖5為顯示形成於導光體背面整面上之散射體圖案之圖 式。 圖6為顯示L = 0 m m時之第二L E D模組的光學特性之圖式。 圖7為顯示L = 6mm時之第二LED模組的光學特性之圖式。 圖8為顯示L = 1 0 m m時之第二L E D模組的光學特性之圖 式。 圖9為顯示L = 0 m m時之第一 L E D模組的光學特性之圖式。 圖1 0為顯示L = 6 m m時之第一 L E D模組的光學特性之圖 式。 圖1 1為顯示L = 1 0 m m時之第一 L E D模組的光學特性之圖 式。 圖12為面狀光源裝置之分解立體圖，其裝置在射出面 側具有遮光板用以覆蓋無效區。 20 312/發明說明書(補件)/92-08/92113 847 1246610 圖1 3為顯示根據本發明的面狀光源裝置的第二實施形 態之分解立體圖。 圖1 4為由背面（印刷面）方向視導光體之俯視圖。 圖1 5為顯示形成於導光體背面的印刷區域上的散射體 圖案與LED模組之間相對位置之圖式。 圖1 6為顯示在第二L E D模組設置面對第一 L E D模組設 置面傾斜1 5 °時之第一 L E D模組的光學特性之圖式。 圖1 7為顯示在第二L E D模組設置面對第一 L E D模組設 置面傾斜1 5 °時之第二L E D模組的光學特性之圖式。 圖18為顯示在第二LED模組設置面對於第一 LED模組 設置面無傾斜時之第一 LED模組的光學特性之圖式。 圖19為顯示在第二LED模組設置面對於第一 LED模組 設置面無傾斜時之第二LED模組的光學特性之圖式。 圖2 0為顯示裝設有第三L E D模組的面狀光源裝置之圖 式。 圖2 1為顯示配置複數個面狀光源之大型面狀光源裝置 之圖式。 圖2 2為顯示影像讀取裝置之圖式，該裝置採用根據第 一或第二實施形態所作的面狀光源裝置。 (元件符號說明） 12 平面導光體 13 背面 14a, 14b LED 光源 16 白色底板 21BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar light source device and an image reading device using the planar light source device, which has a light scattering function on the back side of the light guide body to make the light uniform Shoot out. [Prior Art] A prior art planar light source device is known, for example, from Japanese Laid-Open Patent Publication No. 2000-34. The planar light source device shown in this publication is shown in Fig. 1. The planar light source device shown in Fig. 1 includes a planar light guide body 12 made of a transparent acrylic resin, and the center of the side surface of the planar light guide body 1 on the relatively short side has an LED light source 14a, 1 4 b. Further, a light scatterer is formed on the entire back surface 13 of the planar light guide 12. The bottom surface of the planar light guide body 12 is covered by the white base plate 16 while the peripheral side faces are surrounded by the white frame 18. A diffusion sheet 20 is mounted on the top surface (light-emitting surface) of the planar light guide 12. The planar light source device adopts a device for causing light from a point light source to enter a planar light guide body of a transparent material, and allowing light to uniformly emit light from a two-dimensional planar portion, so as to be an LED light source as a point light source. The light is converted into a luminescent distribution from a planar light source. In addition, each point light source is disposed on the opposite sides of the planar light guide body, and the in-plane luminance distribution caused by the light quantity of one light source and the in-plane luminance distribution by the light quantity of the other light source complement and pass through The in-plane luminance distribution of the sum of the two sides is obtained to obtain the final uniform luminance distribution. However, in the above-mentioned planar light source device, if the LED light source is to be added to realize 5 312 / invention specification (supplement) / 92-08/92113847 1246610 multicolorization and increase in light quantity, the following problems occur: The light from the point source is converted into a light distribution from the light of the planar light source so that the light is uniformly emitted from the two-dimensional planar portion, and excellent precision-adjusted optical scattering must be formed on the back surface of the planar light guide. body. However, the optical scatterers formed on the back side of the planar light guide are typically only tunable for uniform illumination from the illumination from a single L E D module (light from a single point). Adjusted to correspond to the illuminating from a single point (point source), when a new point source is arranged adjacent to it, the deviation of the amount of light is generated for the new point source, and as a result, the luminance distribution on the planar source is uneven. Therefore, it is difficult to install a plurality of LED modules at intervals. Therefore, the L E D module which is inevitably mounted on the planar light guide body due to the above limitation is limited to a single one. Usually, a single LED module (for example, NSCM315C type manufactured by Nissho Chemical Industry Co., Ltd.) is loaded with R (red), G (green), and B (blue), respectively, for a total of 3 wafers. . If more wafers are loaded, the heat-generating components are packaged on a substrate having a limited area, and cooling cannot be performed to cause the entire substrate to heat up, resulting in a decrease in optical performance of the LED. Therefore, for example, on the L E D module in which three L E Ds of R, G, and B are mounted, it is generally impossible to simultaneously load other components, so that it becomes a planar light source that defines the components (number or color). In other words, it is difficult to multi-color or increase the amount of light. In addition, when the light source is installed on the opposite sides of the planar light guide body, the same light source must be used, otherwise the overall uniform luminance distribution cannot be achieved. Only when the same kind of light source is arranged oppositely, the uniform light emission can be obtained by the accumulation of the transmitted light amount, and when the different kinds of point light sources are arranged oppositely, there is no 6 312/invention specification (supplement)/92- 08/92113 847 1246610 The method accumulates the amount of light, so it shows the situation of the amount of light in the in-plane. Moreover, when an LED light source is used, there is a variation in the amount of light although it is the same type. LED light source usually has a large amount of light deviation in the same product, and in terms of specifications, the maximum/minimum ratio of light output capability is 3 to 4 times. If different light output capabilities are matched, they will be multiplied. There is an imbalance and a uniform luminance distribution cannot be obtained. The present invention has been made to solve the problems of the prior art, and an object of the invention is to provide a planar light source device and an image reading device using the planar light source device, wherein the planar light source device is configured to arrange a plurality of LED light sources in a light guide body At the end face, an LED light source capable of realizing a plurality of types (multi-color) or a multi-color (increasing amount of light) or the like is combined. SUMMARY OF THE INVENTION A planar light source device according to the present invention includes: a light guide having an optical scatterer capable of scattering light on a back surface thereof; and a plurality of light sources disposed on an end surface of the light guide; the light guide a body having a region where no optical scatterer exists near the light source on the back surface of the light guide body, so that light emitted from the light source is introduced into the light guide body, and the light is scattered by the optical scatterer and then emitted from the light guide body. Shot out. Further, a planar light source device according to the present invention includes: a light guide having an optical scatterer capable of scattering light on a back surface thereof; and a plurality of light sources disposed on an end surface of the light guide; the light guide; Light emitted from a light source and directed toward a region having a low optical scatterer occupancy per unit area in the region of the optical scatterer on the back surface of the light guide is introduced into the light guide body, and the light is scattered through the optical scatterer Then, it is emitted from the light-emitting body surface 7 312 / invention manual (supplement) / 92-08/92113 847 1246610. Further, the planar light source device of the present invention is characterized in that, specifically, an optical scatterer capable of scattering is provided on the back surface thereof; and the multiplex is disposed on the end face of the light guide; the light guide is disposed at the back of the light guide body A region having no optical scatterer, such that light emitted from a region having a low optical scattering per unit area in the region of the guided optical scatterer is introduced from the light source into the light guide body and scattered by the optical scatterer [Embodiment] Next, a first embodiment of the present invention will be described with reference to the drawings, and FIG. 2 is a first exploded perspective view showing the planar light source device according to the present invention. The planar light source device shown in FIG. 2 is composed of a light guide 21, a reflector for covering the side surface of the light guide body 21, and a reflector having a high reflectance and disposed on the back surface of the light guide body 2, and a reflector 2 4 . The bottom plate 2 5 on the back surface is disposed on the light diffusing sheet 26 disposed on the I surface of the light guide 2 1 . The first LED module 22a and the module 2 2 b are mounted on the light guide body 21 as light from the end surface to the light guide body 2 1; the first LED module 2 2 a is fastened The second LED module 2 2 b is disposed between the center of the side surface of the light guide body and the side edge, and the first LED and the second LED are disposed at the center of the short side of the light guide body 21 The light exit angles of the module 22b are the same module 2 2 a and the second LED module 2 2 b, respectively, and have three LEDs of R (red), G (green), and B (blue) therein. 312/Inventive Manual (Repair)/92-08/92113847 Preparation: Light-guided l light source, the source of the light source is close to the body and the light is emitted. To illustrate. The transparent surface 23 of the embodiment has a short-side module 22a disposed on the side surface 2 of the second LED source. The first LED is adjacent to the 8 1246610 light guide 21, and the size thereof is 27x 50x 3. 5mm, and a transparent acrylic resin is used. A scatterer pattern composed of circular white dots is formed on the back surface of the light guide body 2 by a printing technique. The frame 23 for covering the light guide body is used. White polycarbonate is used on the bottom plate 25, and a diffusion film (100GM2 manufactured by Kibamoto Co., Ltd.) reflection plate 24 is used on the light diffusion sheet 26, and can also be disposed between the light guide body 21 and the bottom plate 25. A material having a high reflectance is used, for example, a material such as a mirror or an aluminum film. The reflectance (reflected light/incident light) of the reflecting plate 24 is preferably higher than 90%. Fig. 3 is the back surface (printing surface) The direction is the perspective view of the light guide body 21. The back surface of the light guide body 21, as shown in Fig. 3, is composed of an area where no optical scatterer (or almost no scattering occurs), that is, an invalid area 27, and printing. There is a printing area 28 formed by a circular white dot, and the ineffective area 27 is provided. The printing area 2 8 is disposed at a certain distance from the first LED module 22 a and the second LED module 2 2 b. 4 is a diagram showing a scatterer pattern formed on the printing area. On the back surface of the light guide body 21, an ineffective area 27 is disposed and printed on a printing area 28 of a certain distance L from the LED module as shown in FIG. The scatterer pattern shown, which is shown here in black, is a circular white point 2 9, and the reflectance of this portion is high. Although a scatterer pattern is formed here as a circular point, it is not limited to a circle. In addition, in the light guide, the length L0 of the light emitting direction of the LED module is 50 mm, and there is no light emitting direction of the LED module in the ineffective area 27 of the scatterer. The length L is 10 mm. 9 312 / invention specification (supplement) / 92-08/92113847 1246610 FIG. 5 is a diagram showing a scatterer pattern formed on the entire surface of the back surface of the light guide body so that When there is only the first LED module 22a at the center of the side surface on the short side of the light guide body 21, uniform illumination is achieved. The scatterer pattern shown in Fig. 4 is a circular white point 2 9 remaining after the circular white point 2 9 at a certain distance L from the side of the LED module is removed from the scatterer pattern shown in FIG. The scatterer pattern formed by the same. Fig. 6 to Fig. 11 are in-planes in a planar light source device having the above-described structure of a light-emitting surface having a size of 25 x 47 mm, in which an electric current is applied to the LED module to cause the planar light source device to emit light. The result of the luminance distribution measurement. The LED modules are disposed on the side of the X-axis value of the light guide body (disposed on the side of 4 7 mm in the figure). As for the luminance meter, BM7 made of T0PC0N is used. A case where R (red) L E D is employed in the first LED module and the second L E D module will be described. In Figs. 6 to 11, the light-emitting surface is represented by an xy coordinate, and a corner of the light-emitting surface is used as a coordinate origin, and the measurement pitch is 1 m m, and the X-axis is equally divided into 4 6 equal parts, and the Y-axis is divided into 2 3 equal parts. The vertical axis is used as the measured luminance (unit is c d / m2). First, the optical characteristics of the second LED module disposed between the center of the side surface of the short side of the light guide body and the side end portion will be described. 6, 7, and 8 are diagrams showing the optical characteristics of the second LED module. Fig. 6 is a view showing optical characteristics when L = 0 m m, that is, when a scatterer pattern is formed on the entire surface of the light guide, and shows optical characteristics when the second LED module of the scatterer pattern of Fig. 5 is used. Fig. 7 is a view showing the optical characteristics when L = 6 mm, that is, when an ineffective area is provided at 6 mm near the LED module, which is removed in the scatterer pattern of Fig. 5 by 6 mm from the side of the LED module. The scatterer behind the round white point Figure 10 312 / invention specification (supplement) / 92-08/92113847 1246610 The optical characteristics of the second LED module. Figure 8 is a graph showing the optical characteristics when L 2 10 mm, that is, when there is an ineffective area near the LED module. The scatterer pattern in Fig. 5 is removed in a circle of 10 mm from the side of the LED module. The optical characteristics of the second LED module when the pattern is after the white dot. As shown in FIG. 7 and FIG. 8, in the optical special setting invalid region of the second LED module (the region where the scatterer pattern is not present), the peak of the large amount of light in the vicinity is reduced, and if the invalid region is made 10 At mm, the peak amount of light is significantly reduced. As a result, the average value of the amount of light removed from the rear printing zone is increased, and an in-plane luminance distribution of the effective area is obtained. In other words, the light emitted from the light-emitting surface after being scattered near the scatterer light source of Fig. 5 is set to be totally reflected and more efficiently conducted backward. Fig. 9, Fig. 10, and Fig. 1 are all showing the optical characteristics of the first LED module disposed at the center of the short side of the light guide. Fig. 9 is a view showing the optical characteristics when L = 0 inm, i.e., when the pattern is formed on the entire surface of the light guide, and shows the optical characteristics when the scatterer pattern LED module of Fig. 5 is used. Figure 10 shows the optical characteristics when L = 6 mm, that is, when there is an ineffective area near the LED module, when the scatterer diagram of Figure 5 removes the circular white point within 6 mm from the side of the LED module. The optical properties of the first group. Figure 1 1 shows the optical characteristics when L = 10 mm, that is, when an ineffective area is placed near the LED module, which is in the scatterer 312 / invention specification (supplement) / 92-08/92113847 of Figure 5. In the case of 0 mm, the length of the LED module is the brighter and uniform pattern of the ineffective area, and the first 5 mm of the side-scattering case on the side of the ineffective area is set. In the pattern of a LED die at 10 mm, 11 1246610 removes the optical characteristics of the first LED module when the circular white point in the range of 10 mm from the side of the LED module is removed. As shown in FIG. 10 and FIG. 11 , in the optical characteristics of the first LED module, the ineffective area (the area where the scatterer pattern is not present) is disposed to reduce the amount of light near the LED module, and the amount of light is reduced. The part is treated as an invalid part. Regarding the use method, for example, as shown in Fig. 12, a light shielding plate 30 is provided on the light emitting surface side to cover the ineffective area to cover the uneven area, so that the uneven area is no longer used. In addition, the visor 30 covering the ineffective area is provided to prevent light leakage from the vicinity of the LED module. As described above, in the first embodiment, when a plurality of LED modules having the same light emission angle are disposed on the light guide body, the ineffective region where the scatterer is not present is disposed near the LED module. It can solve the uneven distribution of luminance generated near the LED module. Because the ineffective area where the optical scatterer does not exist is disposed near the LED module, the optical scatterer formed later in the ineffective area can be observed from a distance farther away (far beyond the ineffective area) by a distance of about several mm. The LED module (point source) allows the entire light source comprising a plurality of adjacent LED modules to be regarded as a point source. In addition, since a plurality of LED modules can be disposed on the light guide body, a variety of L E D planar light sources with increased light amount can be realized. Next, a second embodiment of the present invention will be described with reference to the drawings. Fig. 13 is an exploded perspective view showing a second embodiment of the planar light source device according to the present invention. The planar light source device shown in FIG. 13 is composed of a transparent planar light guide 31 having a chamfered portion 39, a frame 33 for covering the five-sided side surface of the light guide 31, and having a high reflectance and disposed on The reflector 3 4 on the back surface of the light guide 3 1 / the reflector of the invention (repair) / 92-08/92113 847 1246610, the bottom plate 35 disposed on the back surface of the reflector 34, and the light guide 3 1 The light diffusing sheet 36 on the top surface (light emitting surface) is composed of. The first LED module 32a and the second LED module 32b are mounted on the light guide 31 as a light source for injecting light from the end face to the light guide 31. The first LED module 3 2 a is disposed at the center of the side of the short side of the light guide body 31 , and the second LED module 32 b is disposed at the corner portion 39 of the light guide body 31 . . The first L E D module 3 2 a and the second L E D module 3 2 b respectively have three L E D adjacent to each other (R), G (green), and B (blue). The light guide body 31 has a size of 27 x 58 x 3.5 mm. In addition, the light guide body 31 has a chamfered portion 3 9 on the side on which the first LED module 3 2 a is disposed, and the chamfered portion 39 is inclined at an oblique angle of 0 to the first LED mode. Group 3 2 a of light is emitted from the direction of the angle. A transparent acrylic resin is used on the light guiding body 31. A scatterer pattern composed of circular white dots is formed on the back surface of the light guide body 3 by a printing technique. White polycarbonate is used for the frame 33 and the bottom plate 35 for covering the light guide body, and a diffusion film (100GM2 manufactured by Kibamoto Co., Ltd.) is used on the light diffusion sheet 36. The reflectance is higher on the reflection plate 34. High materials, such as materials such as mirrors or aluminum films. The reflectance (reflected light/incident light) of the reflecting plate 34 is preferably higher than 90%. Fig. 14 is a plan view of the light guiding body 3 1 viewed from the back side (printing surface). The back surface of the light guide body 31 is composed of a region where no optical scatterer (or almost no scattering occurs), that is, an ineffective region 37, and a printing region printed with a scatter pattern formed by circular white dots. 3 8 constitutes, as shown in Figure 13. The light guide body 13 312/invention specification (supplement)/92-08/92113847 1246610 3 1 has a length of 58 mm in the light emission direction of the first LED module 32a. The ineffective area 37 is disposed at a distance of 10 mm toward the light emission direction and is disposed near the first LED module 3 2 a, and the printing area 38 is disposed at a distance of 58 mni toward the light emission direction from 10 mm. The first LED module 32a is on. The light guide body 31 has a chamfered portion 3 9 which is angled toward the short side direction at an oblique angle of 0 and directed toward the light emitting direction of the first LED module 32a. The first LED module 3 2 a is disposed at the center of the side of the short side of the light guide body 31 , and the second LED module 3 2 b is disposed at the corner of the light guide body 3 1 . 39 places. Fig. 15 is a view showing the relative position between the scatterer pattern and the L E D module formed on the printing area on the back surface of the light guide. It is shown in black, which is a round white point with a high reflectivity. Although the scatterer pattern is formed by a circular dot here, it is not limited to a circular shape, and may be variously changed in a square shape, a diamond shape, or the like. The first LED module 3 2 a is disposed at the center of the side surface on the short side of the light guide body 31 and faces the region where the scatterer pattern is sparse (the circular white dot occupancy rate per unit area is not high) Area) shot. The second LED module 3 2 b is disposed adjacent to the first LED module 32a, and illuminates the light in the direction in which the light is emitted from the first LED module 32a at an angle of 0 toward a region where the scatterer pattern is sparse (per The area where the area of the circular white point is not high in the unit area is emitted. Figs. 16 to 19 show the results of measurement of the in-plane luminance distribution when a planar light source device emits light by applying a current to the L E D module in a planar light source device having a light-emitting surface having a size of 25 x 44 mm. The LED modules are arranged on the larger side of the X-axis of the light guide (disposed on the side of the 4 4 m 14 312 / invention manual (supplement) / 92-08/92113 847 1246610). As for the luminance meter, Τ 0 P C 0 N is used to make Μ Μ 7. A case where R (red) L E D is employed in the first L E D module and the second L E D module will be described. In Figs. 16 to 19, the light-emitting surface is represented by an xy coordinate, and a corner of the light-emitting surface is used as a coordinate origin, and the measurement pitch is 1 m m, and the X-axis is equally divided into 4 3 equal parts, and the Y-axis is divided into 2 3 equal parts. The vertical axis is used as the measured luminance (unit is c d / m2 ). Fig. 16 and Fig. 17 respectively show the optical characteristics of the first L E D module and the second L E D module when the second L E D module setting surface is inclined by 1 5 ° to the first L E D module setting surface. As shown in Fig. 16, the in-plane luminance distribution of the first LE D module exhibits a relatively flat distribution. In addition, as shown in Fig. 17, the in-plane luminance distribution of the second L E D module can obtain a relatively uniform distribution even when a peak of light is present near the L E D module. In contrast, FIG. 18 and FIG. 19 respectively show patterns of optical characteristics of the first LED module and the second LED module when the second LED module setting surface is not inclined to the first LED module setting surface. . As shown in FIG. 19, the in-plane luminance distribution of the second LED module has a large peak of light near the LED module, which is compared with the optical characteristics of the second LED module shown in FIG. The uniformity is significantly deteriorated. From the measurement results of the in-plane luminance distribution shown in FIG. 16 to FIG. 19, as shown in FIG. 16 and FIG. 18, in the first LED module, no optical is found regardless of whether or not the light guide body has a chamfered portion. Difference in characteristics. Because the light incident into the light guide body (the medium having a refractive index of about 1.5) is almost directional and conducts and advances, and there is no light that can reach the corner portion, the corner portion is not present. The intensity distribution of the influence. In addition, Figure 17 and Figure 19 are compared: In Figure 17, the second LED module is used for the first LED in 15 312 / invention specification (supplement) / 92-08/92113 847 1246610 The tilt of the module is 1 5 °, so that the peak of the light level near the LED module is significantly smaller than that of Figure 19. This is because, as shown in Fig. 15, the light from the second L E D module 3 2 b is emitted toward the region where the scattering pattern is sparse. If the second LED module is inclined by 1 5 ° to the first LED module, the light from the second LED module disposed at the corner portion can be avoided from the LED that causes a large amount of light. The scatterer is printed in the vicinity of the module and faces away from the scatterer farther away, so that light scattering is produced uniformly over the whole. Therefore, the present invention can realize a variety of LED planar light sources with increased light amount by tilting the second LED module toward the first LED module and emitting light toward a region where the scatterer pattern is sparse. As shown in FIG. 17 , regarding the second LED module, a light amount peak is generated in the vicinity of the LED module, so that the light shielding plate 30 shown in FIG. 12 can also be installed (for covering the LED module). There is a region where the peak of the amount of light is generated on the side), and the uneven region is covered and the uneven region is no longer used. The second L E D module can have an oblique angle range of less than 1 ° to 45 °, preferably 5 ° to 30 °. The present invention is characterized in that, when a plurality of L E D modules are provided, as shown in Fig. 15, an angle of inclination is provided in the L E D module to emit light toward a region where the scatterer is sparse. If the oblique angle is small, the distance between the LED module and the scatterer pattern is prolonged, and the intensity of illumination between the distances is not strong, so that the unnecessary portion becomes a large-area planar light source, which is not ideal. . Further, if the oblique angle is larger than 4 5 °, it is difficult to conduct light toward the long side, which is not preferable. In addition, in the second embodiment, as shown in FIG. 15, a scatterer pattern capable of changing the dimensions of the LED module is used to change the light of the LED module. The scatterer pattern is emitted in a sparse area. More preferably, when a scatterer pattern is used which does not change in two dimensions and can only be changed toward the side of the LED module, and thus the scatterer pattern is changed in one dimension from the long side direction which is denser and more dense, The second LED module can be tilted to the first LED module to emit light to the center of the light guide. In addition, in the second embodiment, the decoupling portion is disposed on the light guiding body, and the second LED module is disposed at the chamfering portion, so that the second LED module is inclined to the first LED module. However, it is not necessary to provide a chamfered portion on the light guide body, as long as the second LED module is inclined to the first LED module, and the light is emitted toward the sparsely scattered area, the second LED How to configure the module is fine. For example, the second LED module may be placed on the frame in an inclined manner. Further, in the second embodiment, the light emitting direction of the second LED module 32b is arranged on the light guiding body 31 so as to be inclined with respect to the light emitting direction of the first LED module 32a, but as shown in FIG. As shown in the figure, if the third LED module 3 2 c is disposed on the light guide body 31, the light amount uniformity can be further improved. At this time, if the amount of light at the center increases, the first LED module 32a can be eliminated, and only the second LED module 32b and the third LED module 32c can be left. Further, as shown in Fig. 21, a plurality of planar light sources shown in Fig. 20 are arranged, and a large planar light source device can also be provided. That is, by arranging n light sources, it is possible to produce a light source that is n times larger. In addition, in the first and second embodiments, in the LED module having the LEDs in which R, G, and 相邻 are disposed adjacently, only the 17 312/invention specification using R (red) is used. ()) /92-08/92113847 1246610 LED optical characteristics are described, but each of the R, G, B LEDs are arranged adjacently, so when using G (green) and B (blue) LEDs, The same result can be obtained. Further, the infrared ray L E D is mounted on the first L E D module and the second L E D module, and the infrared ray luminance meter is used for measurement, and the same results as in the embodiment can be obtained. Further, the ultraviolet light L E D was placed on the first L E D mode group and the second LED module, and the ultraviolet light was used for measurement, and the same results as in the present embodiment were obtained. The visible light LED is used instead of the infrared or ultraviolet LED, and since the refractive index of the light guide does not depend on the wavelength, the same result as the visible light is formed. In addition, the first LED module is provided with LEDs of R, G, and B, and the second LED module is provided with LEDs of R, G, and B, and then R, G, and B are synchronized to emit light, because the first LED module And the second LED module is the same color, so the amount of light can be increased. As for the number of LED modules, it is not limited to two, and three or more can be installed. In addition, the first L E D module is provided with L E D of R, G, and B, and the second L E D module is provided with infrared ray E E D to provide a planar light source device capable of coloring R, G, B, and infrared light. Further, by providing the second LED module with the ultraviolet ray L E D , it is possible to provide a planar light source device capable of coloring R, G, B and ultraviolet light. The number of LED modules is not limited to two, and three or more can be installed. Therefore, the first LED module has LEDs of R, G, and B, and the second LED module has an infrared LED, and is also used as a third. The LED module is equipped with an ultraviolet LED to provide a surface light that can illuminate R, G, B and infrared and ultraviolet light 18 312 / invention manual (supplement) / 92-08/92113 847 1246610 source device. Further, a video reading apparatus using the planar light source device according to the first or second embodiment will be described. Fig. 2 is a cross-sectional view showing the image reading apparatus which is an example of the planar light source device according to the first or second embodiment. The image reading device shown in Fig. 2 is a contact type image sensor 46 which is housed in a casing 43. The top surface of the casing is composed of a platform glass 45. A thin film original 4 7 is placed on the stage glass 45, and a planar light source unit 48 according to the above embodiment is provided above the film original 47. The planar light source device 4 8 can be built in a document cover (not shown) or exchanged with the document cover when scanning a thin document. The contact type image sensor 4 6 has a rod lens array 49 and a line image sensor 42 inside, and is disposed close to the terrace glass 45. Further, the contact type image sensor 46 is further provided with a linear illumination device 44 required when reading a paper original, and is turned off when the film original is read. The contact type image sensor 4 6 moves back and forth in a certain direction to read and scan the original. The light incident on the planar light source device 48 is transmitted through the thin film original 47 and then incident on the linear image sensor 42 through the rod lens array 49. As described above, the present invention is directed to a planar light source device in which a plurality of LED modules having the same light emission angle are disposed in a spaced apart manner, and an ineffective region in which no optical scatterer is present is disposed near the LED module. It can solve the uneven distribution of luminance generated in the vicinity of the LED module, and can be configured with a plurality of LED modules, so that a variety of LED surface lights with increased light amount can be realized 19 312 / invention manual (supplement) / 92 -08/92113 847 1246610 Source. In addition, the present invention can solve the uneven distribution of luminance generated in the vicinity of the LED module by emitting light from the LED module toward a region where the scatterer pattern is sparse, thereby realizing various LEDs with increased light amount. Surface light source. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an exploded perspective view showing a prior art planar light source device. Fig. 2 is an exploded perspective view showing the first embodiment of the planar light source device according to the present invention. Fig. 3 is a perspective view of the light guide body viewed from the back side (printing surface). 4 is a view showing a scatterer pattern formed on a printing area. Fig. 5 is a view showing a scatterer pattern formed on the entire surface of the back surface of the light guide. Figure 6 is a diagram showing the optical characteristics of the second L E D module at L = 0 m m . Figure 7 is a diagram showing the optical characteristics of the second LED module at L = 6 mm. Figure 8 is a graph showing the optical characteristics of the second L E D module at L = 10 m m . Figure 9 is a diagram showing the optical characteristics of the first L E D module at L = 0 m m . Figure 10 is a graph showing the optical characteristics of the first L E D module at L = 6 m m. Figure 11 is a graph showing the optical characteristics of the first L E D module at L = 10 m m . Fig. 12 is an exploded perspective view of the planar light source device, the device having a light shielding plate on the exit surface side for covering the ineffective area. 20 312 / Invention specification (supplement) / 92-08/92113 847 1246610 Fig. 13 is an exploded perspective view showing a second embodiment of the planar light source device according to the present invention. Fig. 14 is a plan view of the light guide body viewed from the back side (printing surface). Fig. 15 is a view showing the relative position between the scatterer pattern formed on the printing area on the back surface of the light guide and the LED module. Fig. 16 is a diagram showing the optical characteristics of the first L E D module when the second L E D module is disposed facing the first L E D module setting surface by 1 5 °. Figure 17 is a diagram showing the optical characteristics of the second L E D module when the second L E D module is disposed facing the first L E D module setting surface by 1 5 °. Fig. 18 is a view showing the optical characteristics of the first LED module when the second LED module setting surface is not inclined with respect to the first LED module setting surface. Fig. 19 is a view showing the optical characteristics of the second LED module when the second LED module setting surface is not inclined with respect to the first LED module setting surface. Fig. 20 is a view showing a planar light source device equipped with a third L E D module. Fig. 21 is a view showing a large-sized planar light source device in which a plurality of planar light sources are arranged. Fig. 2 is a view showing an image reading apparatus using the planar light source device according to the first or second embodiment. (Component symbol description) 12 Planar light guide 13 Rear 14a, 14b LED light source 16 White base plate 21
312/發明說明書(補件)/92-08/92113 847 1246610 20 擴 散 片 21 , 3 1 導 光 體 22a ,32a 第 一 LED 模 組 22b ，32b 第 - LED 模 組 18, 23, 33 框 架 24, 34 反 射 板 25, 35 底 板 26, 36 光 擴 散 片 27, 37 無 效 區 28, 38 印 刷 區 29 圓 形 白 點 30 遮 光 板 32c 第 三 LED 模 組 39 去 角 部 42 線 形 影 像 感 測 器 43 外 殼 44 線 形 昭 t \>\ 明 裝 置 45 平 台 玻 璃 46 接 觸 型 影 像 感 測器 47 薄 膜 原 稿 48 面 狀 光 源 裝 置 49 桿 狀 透 鏡 陣 列312/Invention Manual (supplement)/92-08/92113 847 1246610 20 diffuser 21, 3 1 light guide 22a, 32a first LED module 22b, 32b first-LED module 18, 23, 33 frame 24, 34 Reflector 25, 35 Backplane 26, 36 Light diffuser 27, 37 Invalid area 28, 38 Printed area 29 Round white point 30 Light shield 32c Third LED module 39 Degusset 42 Linear image sensor 43 Housing 44 Linear shape \ \ \ gt; \ Ming device 45 platform glass 46 contact image sensor 47 film original 48 planar light source device 49 rod lens array
312/發明說明書(補件)/92-08/92113 847 22312/Invention Manual (supplement)/92-08/92113 847 22